Apparatus for producing inert gases



Jan. 3, 1956 H. v. WILLIAMSON 2,729,546

APPARATUS FOR PRODUCING INERT GASES Original Filed Nov. 18, 1948 5 Sheets-Sheet l j 5a 74 J6 @a @Z 46 .5f

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ATTORNEY H. v. WILLIAMSON 2,729,546

APPARATUS FOR PRODUCING INERT GASES Jan. s, 1956 5 Sheets-Sheet 2 Original Filed Nov. 18, 1948 f HNVENTOR #my WwW/mm my( @WM I www Jan. 3, 1956 V H. v. wlLLlAMsoN 2,729,546

APPARATUS FOR PRODUCING INERT GASES original Filed Nov. '18, 194e 5 Sheets-Sheer s ATTORNEY Jan. 3, 1956 H. v. WILLIAMSON 2,729,546

APPARATUS FOR PRODUCING INERT GASES Original Filed Nov. 18, 1948 5 Sheets-Sheet 4 '/f//mf #Mm/f By g ATTORNEY Jan. 3, 1956 H. v. WILLIAMSON 2,729,546

APPARATUS FOR PRODUCING INERT GASES Original Filed Nov. 18, 1948 5 Sheets-Sheet 5 ATTORNEY United States Patent() APPARATUS FOR PRODUCING lNERT GASES Hilding V. Williamson, Chicago, lll., assignor to Cardox Corporation, Chicago, Ill., a corporation of Illinois Original application November 18, 1948, Serial No. 60,755, now Patent No. 2,624,711, dated January 6, 1953. Divided and this application June 9, 1952, Serial No. 292,429

Claims. (Cl. 23-281) This invention relates in general to new and useful improvements in apparatus for producing a homogeneous mixture of inert gases, and more particularly to apparatus for burning a carbonaceous material in the presence of atmospheric gases to form a homogeneous mixture of gaseous products of combustion from which free oxygen and carbon monoxide have been substantially eliminaied. This is a division of the application of Hilding V. Williamson, Serial No. 60,755, filed November 18, 1948, for Method andApparatus for `Producing Inert Gases, now Patent No. 2,624,711, issued January 6, 1953.

There is in modern industry, an ever increasing demand for a practical, inexpensive and relatively portable device for supplying a mixture of inert gases for use in Water purification systems, inerting spaces, food preservation and other similar applications. For use in these fields, it is essential that such a mixture of gases be C relatively free from oxygen, carbon monoxide, water vapor and other like impurities. For many purposes, it is essential that the carbon dioxide percentage of the gaseous mixture be maintained at a uniform, high level throughout any variations in the output of the device. And finally, the maximum output of the device should be as high as possible in accordance with its size and portability.

It is, then, the primary object of this invention to provide apparatus for combining the free oxygen of atmospheric air with carbon to form a homogeneous mixture of inert gases containing a relatively high percentage of carbon dioxide with a minimum of carbon monoxide and residual free oxygen.

A further object of the invention is to provide a device adapted for burning a solid carbonaceous material in the presence of atmospheric oxygen producing an inert gas mixture in controllable amounts; the maximum producible amount being relatively high, and the carbon dioxide content of the mixture being uniform and relatively high throughout the entire control range while the active gas impurity content is maintained at an absolute minimum.

A further object of the invention is to provide apparatus for producing a homogeneous mixture of inert gases containing a relatively high percentage of carbon dioxide and a minimum of active gas impurities by controlling the temperature and oxygen content of a gaseous mixture which is passed through a bed` of solid carbonaceous material to cause the oxygen inthe mixture to combine with the carbon in the material to form `carbon dioxide.

Still another object of the invention is to provide ap-` paratus tor producing an inert gas mixture by passing a mixture of gases containing a controlled amount of oxygen and at a controlled temperature through a bed of carbonaceous material whereby the oxygen is combined with carbon to form carbon dioxide at a controlled reaction temperature to cause the mixture of inert gases to con tain a relatively high percentage` of carbon dioxide and a minimum of active gas impurities.

A still further object of the `invention-,is to provide a flange 19 on the upper margin oi the side Wall.

2,729,546 vPatented Jan. 3, 19,56

ice

apparatus for producing a mixture of' inert gases having a relatively high carbon dioxide content and a minimum of active gas impurities by passing a mixture of gases having a free oxygen content ot approximately two to three per cent and at a temperature of 1000 F. to 1200 F. through a bed of carbonaceous material to cause the oxygen to combine with the carbon to form carbon dioxide at a reaction temperature of l400 F. to 1600" F.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a vertical sectional view of an inert gas producing unit illustrating an embodiment of the invention,

Figure 2 is a plan view of the unit illustrated in Fig. l,

Figure 3 is a horizontal sectional view taken on line 3--3 of Fig. 1,

Figure 4 is a horizontal sectional view taken on line 4-4 of Fig. 1,

` Figure 5 is a horizontal sectional view taken on line 5 5 of Fig. l,

Figure 6 is a diagrammatic view of the electric circuit employed as a part of the unit illustrated in Fig. 1,

Figure 7 is a schematic view of the pneumatic system that is controlled by the electric circuit illustrated in Fig. 6,

Figure 8 is a vertical sectional view of a modified form of inert gas producing unit to that illustrated in Fig. 1,

. Figure 9 is a horizontal sectional View taken on line 9 9 of Fig. 8, t

Figure l0 is a horizontal sectional view taken on line 14)-10 of Fig. 8,

Figure 11 is a detail perspective view of the upper portion of the venturi tube illustrated. in Fig. 8, and

Figure 12 is a fragmentary horizontal sectional View illustrating a modification in the cooling coils of the units shown in Figs. 1 and 8.

in the drawings, wherein for the purpose of illustration, are shown the preferred embodiments of this invention, and referring first to Fig. l, the numeral 15 designates a housing having a side wall 16 and a cover plate 17 which is connected to the side wall by the bolts Y18 passing through the outer margin of the cover plate and A sealing member 20 is positioned between the cover plate 17 and the iiange 19 to prevent pressure leakage at the connection therebetween.

The lower end portion of the side wall 16 is provided with a iianged ash removal opening 21 having a seating surface 22. A quick opening door 23, see Figs. 1, 2 and 3, is provided for the opening 21 and has a sealing member 24 for engagement with the seating surface 22. The transverse hinge members 25 are provided with a freely rotatable hand-wheel 26 having a threaded stem 27 for engagement with the internally threaded collar 28 which is connected to the outer surface of the door. The free end portions of the transverse hinge members 25 are pivotally connected to a latch bar 29 having a hooked outer end portion 30 which is engageable With the latch plate 31 when the door 23 lies across the opening 21 as illustrated in Fig. 2.

, When the hooked end 30 of the latch bar is engaging the latch plate 31, the hand-wheel 26 may be rotated to cause relative axial movement between the stem 27 and the collar 2S whereby the sealing member 24 is forced into pressure sustaining engagement with the seating surface 22 and the hook 3) and latch plate 31 are maintained in their engaged position by the resulting forces therebetween.

similarly' 'hstreted diiiek opening door 32 is located on the cover pl'ate'17t'o 'provide a pressure sustaining closure for the fuel supply opening 33 of the latter. Therefore, like reference numerals are employed to desig-` nate the corresponding pa'r't'sof each door.

The lower portion 'of the side 'wan 16` and the bottom plate 34 of the housing are provided with an en'casedpinternal layer of suitable heat insulating material 35. The upper 'annular surface 36 of the casing of the insulating material inside the side wall 16 is sloped downwardly and inwardly relative to the sidewall. g Y

. A supporting ring 37 extends circumferentially around the inner Asurface of the casingfor the side wall insulating material `35, 'and ismsuitably connected thereto. The per- 'forated 'grate bars '38 'are pivotally connected to the supporting ring 37Aby the pins 38a and extend downwardly and inwardly therefrom in' :spacedrradi'al relationship to be pivotally connected by 'the pins 38,11 at their inner, lower erid portions tothe shaker rring 39. A shaker bar V40 is rigidly connected to the shaker ring 39 and extends outwardly therefrom to pass through the slot 41 in the crnk'arm 42. The shaft v43 of the crank arm passes through the side wall 16 and the encased insulating mateffial 35 in "afmanner v`to prevent escape of gases, and is rigidly connected to the handle 44 as illustrated in Figs. land 3.

When the handle 44ris actuated, the 4crank `arm 42 operates to oscilla'te the-shaker lbar 40 and the shaker ring 39. This movement of the 'shaker ring 39 is'irnparted to the grate Abar's'3'8 Ito cause their relative'fmovement to agitatc the ash resting thereon.

A Calrod type electrical heating element 45 is positioned beneath the ir'ne'dial portion ofthe grate bars 38 and the electrical terminals thereof are passed through lthe encased insulating -rnaterial 35 and the'side 4itf'all -16 of the housing where they are sealed to prevent escape of gases from the'housin'g. Y y

A cylindrical stack 46 is positioned `coaxially of the housing-1`5 in the upper `portion thereof, 'and is 'provided with 'a sealed c'ove'r`47 which is positioned `:slightly above the cover plate 17. `A truncated vconical lmember 48 Ais connected to the lower edge of the stack 46 "arid'extends downwardly and outwardly therefrom to A`terminate l:in spaced relation to the lower margin ofthe 'aforesaid annularsurface 36 thereby forming la hopperh'charnber 49 b ounded 'by the side wall 16, the coverV plate 17, the stack 46, the conical member 48, and th'e annular surface 36. The opening 33 provides an inlet tothe `chamber 49, and the space between the conical member "48 andthe annular surface 36 provides an'annular discharge'opening above the outer portion of the grate bars 38.

The space below the stack v46 andthe conical -member 48 and above the grate bars 38 Avserves Aas a combustion chamber, receiving itsfuel supply from thehopper charnber 49 through the discharge opening thereof.

The stack'46 is provided witha discharge opening'46a located between its'cover '47 and the coverplate 17 'ofthe housing for withdrawing gaseous productsof combustion from the housing.

rA cylindrical tube 50 isrigidly connected to the inner surface of the stack cover 47 by the flanged ring 51 to form a cooling chamber 51a between the `cap 52 for the tube 50 and the cover 47. The etube'50 extends 'downwardlyv through the stack 46 to a point slightly fbelow the lower margin of the latter. This tube'is provided with four openings 53 at equally spaced circumferential `intervals around its lower end portion. The upper end portion of the tube 50 isprovided with asimilar series of four equally lspaced openings 4 that are 'longitudinally alined with the lower openings 53, as illustrated'in Figs. l, 4 and 5. j Y

Thecap 52 is provided with a central opening l55 sur rounded-by a cylindrical projection 56 which extends above the stack cover 4 7 to receivetlieair inlet Ipipe57 through the packing gland 58. The air inlet pipe passes` through the cap 52 and centrally of the tube 50 to terminate in a vv 'tifctl l '59 fra' the lWer pe'igs 53.

The upper end portion of the air inlet pipe 57 is connected to the compressed air supply pipe 60 through the swivel joint 61 and valve 62 controls the flow of compressed air through the pipe 57.

A plate 63 is welded or otherwise connected to the air inletv pip'e'57 beneath and closely adjacent to the cap 52. Y

An aspirator tube 64, having an internally flanged upper end portion 65, is connected to the plate 63 by the bolts 66. The aspirator tube 64 is concentrically positioned within thetube 50, with a minimum clearance to allow relative rotation therebetween, and extends downwardly through the shaker ring 39 to the space below the grate bars 38. A series of four equally spaced openings 67 are located circumferentially at the medial portion of the aspirator tube 64 and a similar series of four openings 68 are located at the upper end portion of this tube. The upperV openings 68 are displaced angularly 45 degrees with respect to the lower openings 67, as illustrated in Figs. `1,"4 and 5. The location of the openings 67 and 68 in the aspirator Ytube 54 and the openings 53 and( 54 in the tube 50 are such that the aspirator tube may be rotated to radially aline the openings 67 and 53 at which time the openings 63 are disalined radially with the upper openings 54. The openings 68 and 54may also be radially alined by rotation of the [aspirator tube 64, but when so alined the openings`67 and 53`a're disalined radially.

It will be Iseen that Vthe above discussed openings inthe tubes Sil and 64"are so arranged that the ltubes cooperate byrelativerotation to 'function as aselector valve for controlling the path of ow of the gases.

A venturi type how noz'zle 69 is positioned Vwithin the lower portion of the aspirator tube 64 so that the lfiow restricting "air 'no'z'Zle 59 points into the converging inlet of the venturi, and the space between the venturi '69 and the aspirator tube 64 is filled with a suitable heat insulating material 70.

Ash agitatirrg ns 71 are connected to the outer surface of the lowerend portionof the aspirator tube 64 and extend longitudinally thereof.

lLA double layer cooling coil 72 is positioned within the stack 46 outwardly of the tube 50. The upper end por-V tion 73 ofthe outer layer of the coil is connected to the cooling chamber 51a so that a vlcontinuous flow path for the water, lor 'other cooling medium, is Iformed. This ilow-pathin'cludes the cooling chamber 51a vand cooling coil 72,*havin'g'an inlet 74 into the cooling chamber, Vand anv outlet 75 at the upper end of the inner layer of the coil.

`By referring to Figs. 1, 2 and '7, it will be seen that the air inlet pipe 57 is vertically supported for rotary movement by the vball type thrust bearing l76 resting on tl'iesupport 77 and carrying the'split clamp 78 which is rigidly connected'to the pipe. Arr operating lever 79 is rigidly connected tothe split clamp 78 andlpivotally connected tothe rod80 of the double acting piston 81. The piston 81 is movably rnountedin the cylinder 82 which is pivotally mounted on the cover plate 17 and provided withrlpressure supply lines 83 and`8'4.

Referring "now -to Figs. '1, 6 and 7 for a detailed descriptionof an automatic temperature control system for the unit, the temperature responsive control element 185, located Vin thespacebelow lthe-grate bars 38, is lforrned 'of anV outer tubular member `v86 andan internal 'rod Y87 having a low "thermal coeicient of expansionrelative tothe tube 86. One endrportionof the tube 86 is` positioned di rectly beneath the outlet of the venturi 67, and the inner rod 87 yis fastened tothe tube'at this end. The other end'f the2tube86 is Eprojecte'd through the side wall 16 :in lsealingengagement therewith, and the corresponding end .portion of the rod 87 projects -fr'orn theen'do'f vthe tube. Expansion and contraction fof-'the tube v86 will therefore cau/se the project-ingferidpoition of the' tube "87 to move irfrwardly-nd outwardly, respectively, rel'at'ive'to '5 the side wall 16. This movement of the rod 87 serves to operate a switch 88 to open and close, respectively, the electrical circuit through the wires 89 and 90.

As is illustrated in Fig. 6, the wire 89 is connected to one side of an electric supply source, not shown, and the wire 90 is connected through the coil of the solenoid 91 to the other side of the supply source.

The movable armature 92 of the solenoid is pivotally connected to the valve operating lever 93 which is mounted for pivotal movement above the pin 94. A pair of valve operating rods 95 and 96 are slideably mounted in the valve body 97 in such a manner that the outer end portions of the rods may freely engage the operating lever 93 on opposite sides of the pin 94.

The inner end portions of the rods 95 and 96 are adapted to freely engage the movable balls 98 located, respectively, within the chambers 99 and 100. Each of chambers 99 and 100 is provided with an inlet 101, an outlet 102 and a vent 103. Movement of the valve operating rods 95 and 96 in their respective chambers moves one ball 98 to close the inlet 101 of one of the chambers and simultaneously releases the ball 98 in the other chamber to permit pressure air to flow through its inlet 101. Further, the vents 103 of the chambers are so positioned that movement of the balls 98 toward or away from the inlets 101 causes the vents to be closed and opened, respectively, as the inlets 101 are opened and closed. The outlets 102 remain open at all times, and are connected to the pressure supply lines 83 and 84 leading to the cylinder 82.

The inlet openings 101 of the chambers 99 and 100 are connected by the pipe 101a to a source of supply of compressed air, not shown, which may be the same source as that to which the compressed air supply pipe 60 is connected.

In operation, the weight of the solenoid armature 92, supplemented by a spring if necessary, forces the lever 93 into its depressed position when switch 88 is open and no current is flowing through the solenoid 91. In this position the compressed air admitted to the chamber 99 is directed through its outlet 102 and the pressure supply line 83 to force the piston 81 to the opposite end of the cylinder 82, as viewed in Fig. 7. The air which is displaced from the cylinder 82 is exhausted through the pressure supply line 84 and the outlet 102 of the chamber 100 to be vented through the now open vent 103 in the chamber 100. The inlet 101 of the chamber 100 is closed to prevent escape of the compressed air through the open vent 103.

When the solenoid 91 is energized, as illustrated in Fig. 7, the lever 93 is raised by the solenoid armature 92. In its raised position, the lever 93 reverses the operating conditions of the chambers 99 and 100. Compressed air is admitted to the chamber 100 and passes through supply line 84 to enter the cylinder 82 to force the piston 81 to the opposite end thereof and to exhaust the air on the opposite side of the piston 80 through the line 83 and the vent 103 in the chamber 99.

Referring now to Figs. l through 7 for a description of the operation of the above described unit, the hopper chamber 49 is supplied with coke through the opening 33 until the coke passing through the bottom discharge opening onto the grates 38 has formed a bed B of surticient depth to prevent further discharge. A reserve supply of coke, preferably, is maintained in the hopper chamber. The door 32 is then closed and, with the hooked end 38 of the latch bar 29 engaging the latch plate 31, the hand-wheel 26 is rotated to force the sealing member 24 into sealing engagement with the seating surface 22. The door 23 is similarly closed and sealed to prevent escape of gases through the ash removal opening 21.

The heating element 4S is energized for a sufficient length of time to raise the temperature of the coke bed B to approximately 1000"` F. Vat which point compressed air from a suitable supply source is admitted at a cona stant pressure through the valve 62 in the supply line 60 to the air inlet pipe 57. The heating element is then deenergized.

The compressed air entering the air inlet pipe 57 is directed downwardly from the flow restricting nozzle 59 as a high velocity jet, and enters the venturi 69. The velocity of the air discharged by the nozzle 59 is increased and its static pressure is decreased so as to create a pressure drop of from iive to ten pounds per square inch in the passage of the air from the nozzle 59 through the throat of the venturi. This pressure drop creates an aspirator etect so that gases are drawn through either the openings 67 and 53, communicating with the combustion chamber, or through the openings 68 and 54, communieating with the upper portion of the stack 46, depending upon the relative positions of the tube 50 and the aspirator tube 64 and the openings that are radially alined. The gases passing through the alined openings are entrained in the air stream at a ratio of from six to ten volumes of entrained gases for each volume of air.

The air and entrained gases are thoroughly mixed during their passage through the venturi 69, and are delivered to the space below the grate bars 38. From this space the air and gas mixture flows upwardly into the fuel bed B through the perforations in and the spaces between the grates 38. The oxygen content of the mixture of air and gases Will vary from approximately three per cent, when the ratio of entrained gases to air is six to one, to approximately two per cent when the ratio is ten to one.

The temperature of the mixture depends primarily upon the temperature of the entrained gases, and is controlled by the temperature responsive control element 85 to within a range of 1000 F. to 1200" F. The mode of operation of the temperature control system is as follows:

When the temperature of the mixture of air and entrained gases drops to 1000 F., the gaseous mixture issuing from the Venturi 69 and contacting the element 85 will cause the tube 86 to contract sufficiently to move the rod 87 outwardly to close the switch 88. The circuit through the solenoid 91 is then closed by the switch 88 and energization of the solenoids causes operation of the valve 97 to bring about movement of the piston 81 to the left-hand end portion of the cylinder 82, as shown in Fig. 7.

Fig. 2 illustrates that this movement of the piston 81, and its attached piston rod 80, will cause the operating lever 79 to pivot in a counter-clockwise direction, Whereby the air inlet tube S7 and its attached aspirator tube 64 will be rotated in the same direction. The length of the piston stroke is such that rotation of the aspirator tube 64 is limited to the 45 degrees necessary to place the openings 67 in the aspirator tube in alinement with the openings 53 in the tube 50, and to disaline the openings 54 and 68 at the upper end portions of the tubes 50 and 64.

The entrained gases are, therefore, drawn from the combustion chamber directly above the fuel bed B where their temperature is at or near the maximum. This results in an increase in the temperature of the mixture of air and entrained gases contacting the element 85 so that the tubular member 86 will expand to retract the rod 87 and open the switch 88 in the circuit through the solenoid 91.

As the solenoid 91 is deenergized, valve 97 is operated to cause the piston 81 and its piston rod 80 to move to the right of Fig. 7, as herebefore discussed.

Movement of the piston rod in this direction will pivot the operating lever 79 and rotate the attached air inlet pipe 57 in a clockwise direction to rotate the aspirator tube 64 to the position where the openings 54 and 68 are alined and the openings 53 and 67 disalined.

The entrained gases will then be drawn from the upper portion of the stack 46 after having passed in contact with the cooling coil 72. The entrained gases are, therefore,

af a "ferile'rat'ure'ttlian 'those-gases 'ldirectly 'above die lfuer lieu un. fana the "tempjerautre of the mixture er air aii'dfeitifain'ed gse's will lraccordingly be reduced.

To summarize the above description of the -mode of operation,l thel'mixtureof air and entrained gases :is 'delivered to the A'bottom fof 'th'e fuel bed AB at a temperature of 21000" Fito-11200: F. and 'with yan oxygen content of from two to fthree iper zcent, where the oxygen supports combustion ofthe coke.

`lDuringfthe passa'g'eof the lmixture through the coke bed fB, fmost-of the oxygen is combined with the carbon in ithe coke to iformrcarbo'n dioxide and the temperature increases approx-imately l200" for each one per -cent of oxygen Icontained Vin the mixture. The temperature of the gaseous fproducts of combustion leaving lthe top of-the `fuel bed iB lwill, therefore, ordinarily range from 1400"?. to `160091:.

A portion of the gaseous .products 'of combustion rising from -the fuel bed lB are :then entrained and recycled with the incoming air to make the process Vcontinuous and complete. The 'recycled gases may contain a vsmall amount 1of carbonlrnonoxide'due to incomplete combustion '-in the fuel bed B, but 'the temperature of the air and recy'cled fgas mixture is Vsuch that substantially all of the carbon monoxide 'combines with oxygen in the 'air beforelreentering the fuel bed B.

'The finert fgas niixtu're, lwhich is discharged from the unit zthrough `the 'discharge opening 46a in the ystack 46, consists 'primarily of inert atmospheric gases and from nineteen'to twerityip'ercent carbon dioxide with less than two-'tenths percent free oxygen and less than tive-tenths per'centcarbonmonoxide Variations in the amount of constant pressure air supplied will vnot appreciably atect the consistency of the'discharged gases.

The .maximum outputV is increased by operating the unit gwith internal pressure of up to twelve pounds per squarciinch,igage. Asfthe internal pressure is increased, the velocity 'of the 'recycled gases and the air passing through the `fuel Vbed .B `:will be `reduced to extend the length of time during which combustion may take place.

During'operationioftheunit, the grate handle 44 may be"1a`ctuated1to'move Ithefgrate bars 38 whereby the ashes wil1`ltervthrough therbars and collect in the bottom of the-'housing 15. `Operation ofthe grate bars 38 will also facilitate settling of the fuel bed B as Vcombustion occurs to "allow`fuel ito feed linto the combustion chamber 'from the Ihopper y"chamber I49. The iins l71 on the aspirator tube T64 fact -tofurthe'r 'agitata the fuel bed B when 'the aspirator tube is rotated Ito control the .temperature of the :mixture Ivof air andientrained gases. The ashes collected'in-thetbottom'of thevhousing 16 are removed from the housing throughfthe vash removal opening 21.

,Referring vnow `to Figs. `8 through 1l, wherein is illustrated amoditc'ation of the embodiment of the invenhousing having a side wall 106 and an integral bottom plate 1107. Theiuppereend portion of the side wall A106 is'ranged'outwar'dly' to providea seating surface l108 for the cover plate 109. The cover plate 109 is connected to the -upper e'nd portion-of the side wall 105 by the bolts 1-10 Fin la'fma'nnerj to prevent the leakage of gases therebetween.` p l V.Thefcov'er,plate 109 is provided with'a hanged opening 111 having a seating surface 112. A door 11.3.is hinged ,forV movement Vto fclose the opening r111, kand is provided withfa'transverse latch bar 114 having a slotted end portion 111-5 forlreceiving the stud 116 so that the door :113 *ni-ay be 4locked in its closed position by the wing 'nut :117.

The lower :portionof the side wall 5106 is provided with an encasedinternal layer of suitable heat insulating material 118. Theiupper annular surface 119 of the casing :of 'the insulating material :inside the lside `wall 106 r'is-sloped downwardly and Vinwardly relative to `the sidewall.

'support '127 4-is il'anged, outwardly.

Anashcollectng hopper iis positioned in thelew'er portion' tof' the y'housing ,105 'so that fits downwardly VSinclined surface extends 'from the casing of the insulating material 118 -to `a centrallyf'located opening 121. vAn 'ash blow-off pipe "122 provides a passageway from `-the opening '12f1toa valve 1-'23 outside the housing 105. The point at which the ash vblow-off pipe 122 passes ithrough vthe lower fend /portion -of -the side wall 106 is provided with -a sealing device 124 toV prevent 'escape of gases from `the .housing 105.

A perforated `conical grate 125 is positioned in the lower portion of the housing 105 where it is connected to and extends downwardly and inwardly from the casing of the insulating Vmaterial i118 Vfin spaced relation to the ash `collecting"-hopperfl-Z. The lower portion of the grate `l25 -is provided with -a centrally located opening.

As illustrated in Figs.' 8 and 10, a s'eriesfofv four equally spaced support -bars 126 extend 'radially inwardly from 'the casing-ofthe insulating material 4118 below the grate 125 to receive the=cylindrical shakersupport 127 which is concentrically flo'cated with respect to the axis `ofthe housing 105 and extends upwardly through the opening in the -g1"ate12`5. The upper end portion of the shaker An annular shaker ring' 128, 'having a toothed, Vbeveled outer edge i129, fis held in position around the shaker support by the ring 130. The shaker ring 128 is thereby rotatable `about the' shakenisupport, and yis 'provided with a series of equallyspaced, 'radially extending ribs 131 Aon the upper surface thereof. Y w Y A shaker-crank 132 extends through the side wall 106 of 'the housing '105 in' such a manner as to preventV escape of vgases from fthe housing, and is supported .near its 'innerlend portion bythe 'transverse supporting member 133 whichY is connected between adjacent support bars1-2'6. The -inner 'end fportion ofthe shaker crank 131isfprovide'd with a beveled gear 134 for engagement with'lthe toothedouter edge 129 of the shaker ring 128.

' Ai'Calrodtype electrical'heating element 135 -is positioned beneath the medial portion of the grate 125 and has electrical 2terminals passing through the encased vinsulating material 118 and the side wall 106 of the housing where they 'are sealed to prevent escape of gases from the housing 105.

Y Afcyiindrrcai stack rss is positioned ceaxisny Vof sie housing 105 in the upperportion thereof, and is provided with a'fsea'ledcover 137 which is positioned above the cover plate 109,. VThe stack 136 is provided with a discharge openingflS'S located between its cover 137 and the cover plate 109 of thehousing for withdrawing gases from 1the stack. A llange `139 extends inwardly from the -lower 'end portion of the stack 136 to provide a centrally located circular opening Vin the bottom of the stack.

A"fh`ollow1trunc'ated conical member 140, filled with a 'suitable heat insulating material `141, is connected vto and extends downwardly and outwardly from the flange 13910 terminate in spaced relation to the inclined annular' surface' 119 thereby' forming a hopper chamber 142 bounded by the sidewall 106, the cover plate 109, thesta'ck 136,the conical member 140, and the annular surface' 11,9. ,"The opening 11'1 provides an inlet to the chainberlZ and the spacebetween the conical member 1'40 and the .annular surface 119 provides an yannular discharge openingabove theouter'portion of the grate 125.

The 'space -below the conical member 140 and above the grate 125 servesas 4a combustion chamber, receiving its `fuel `supply .from the Vhopper chamber 142 through Y its discharge opening. t

.-An :encased iventuri itubeY 143,.'having heat insulating material 1144, isI suspended lfrom thevtianged 'surface @139 by the :four fequallyffspaced .ngers 145 yto extend 'newnwardly through the cylindrical shaker support 127 to the space below the grate 125.

The stack cover 137 is provided with a central opening for receiving the air inlet pipe 146 which passes through the opening in sealing engagement therewith and extends vertically downwardly through the stack 136 to terminate in a tiow restricting nozzle 147 slightly above and concentric with the inlet of the venturi tube 143. The valve 148 located in the air inlet pipe 146 acts to regulate the flow of air through the pipe 146. The portion of the air inlet pipe 146 within the housing 105 is provided with a series of four equally spaced iins 149 extending longitudinally thereof.

A movable cylindrical tube 150, positioned between the inlet of the venturi tube 143 and the cover 137, is of such a length as to permit vertical movement between the venturi and cover. The tube 150 is guided in its vertical movements by the iins 149 contacting its inner surface, and the spaced lingers 145 contacting the lower end portion of its outer surface. An operating rod 151 is fastened to the upper end portion of the tube 150 and extends vertically therefrom through the stack cover 137 in such a manner as to permit vertical movement of the rod and prevent escape of gases from the housing 105. The upper end portion of the operating rod 151 is pivotally connected to the operating handle 152 by the pin 153 passing through the slot 154 in the latter. One end portion of the operating handle 152 is pivotally connected to the vertical post 155 which is mounted on the stack cover 137 p It will be seen that when the operating lever 152 is raised to its uppermost position, the operating rod 151 will lift the tube 150 so that its upper end portion will contact the stack cover 137. When the tube 150 is thus contacting the inner surface of the cover 137, the lower end portion of the tube 150 will lie in spaced relation to the inlet of the venturi 143. When the operating lever is moved to its lowermost position, the lower end portion of the tube 150 will contact the venturi tube 143 and the upper end portion of the tube will lie in spaced relation to the stack cover 137. Intermediate positions of the operating handle 152, between its uppermost and lowermost positions, will provide for locations of the tube 150 to vary the space between the lower end portion of the tube and the inlet of the venturi and the upper end portion of the tube and the stack cover 137. The tube 150, therefore, acts as a selector valve for controlling the flow of gas into the venturi through the spaces at either the bottom or the top end portion of the tube.

As illustrated in Figs. 8 and 9, a double layer cooling coil 156 is positioned within the stack 136 outwardly of the tube 15o. The upper end portions of the inner and outer layers of the coil are extended through the stack cover 137 to provide the inlet and outlet for the water or other cooling medium which is to flow through the coil. The lower endportions of the inner and outer layers are connected to form a continuous flow path.

A pyrorneter 157 is mounted on the housing so that the temperature responsive portion 158 thereof is located beneath the grate 125 and extends outwardly through the encased insulating material 118 and the side wall 106 in such a manner as to prevent the escape of gases from the housing 155. The indicator dial 159 of the pyrometer is conveniently located outside the housing 105.

The operation of the modified unit illustrated in Fig. 8 is the same as that of the modification illustrated in Fig. 1 herebefore disclosed, with the exception of the manually operated temperature control system and the manner in which ashes are removed from the lower portion of the housing. The operation of the unit illustrated in Fig. 8 will, therefore, be discussed at this point only insofar as the temperature control and ash removal systems are concerned.

It will be recalled, that the temperature of the mixture of air and entrained gases in the space below the grate is to be maintained within the range of 1000 F. to 1200 F. The portion 158 of the pyronieter 157 responds to changes in the temperature of the surrounding gas as indicated by the dial 159. The operating lever 152, therefore, may be manually actuated for adjusting the tube to regulate the ltemperature of the entrained gases when necessary to properly maintain the temperature within the desired range as indicated by the pyrometer indicating dial 152.

The mode of operation of the tube 15) in controlling the temperature of the gas and air mixture will now be described.

When the temperature indicated on the dial 159 rises to approximately 1200 F. the operating handle 152 should be depressed to place the lower end portion of the tube 150 in contact with the inlet of the venturi 143. In this position, the tube 150 provides a ow path for the gases to be entrained in the venturi through the stack 136 in contact with the cooling coil 156, then downwardly along the inner side of the tube 151). The passage of the entrained gases in contact with the coil 156 cools the gases suiliciently to reduce the temperature of the mixture of the air and entrained gases so that their temperature will drop.

When the temperature indicated by the pyrometer dial 159 drops to 1000 F. the operating handle 152 should be lifted to cause the upper end portion of the tube 150 to contact the inner surface of the stack cover 137. In this position the aforementioned iiow path to the venturi 143 is closed and the entrained gases will be drawn directly from the combustion chamber through the space between the lower end portion of the tube 150 and the inlet of the venturi 143. The gases in the combustion chamber are' at a higher temperature than those pass ing over the cooling coil 156, and the temperature of' the air and entrained gases will, therefore, be increased to prevent a temperature drop to below the prescribed limits.

It will be appreciated that adjustment of the operating lever 152 to a position intermediate to its uppermost and lowermost positions will adjust the tube 154) to provide for the liow of entrained gases through both the space below the lower end portion of the tube 150 and the space above the upper end portion of the tube 150., Part of the entrained gases under these circumstances will' be cooled so that a balanced condition may be reached where further adjustments of the tube will be slight and infrequently required.

The ashes which are collected in the ash collecting hopper 120 may be periodically removed during operation of the unit by opening the valve 123 whereby the pressure within the unit will cause the ashes to be blown through the opening 121 and the pipe 122 to be discharged from the unit.

Fig. l2 illustrates a modified cooling coil 16@ which may replace the cooling coil 156 of the unit illustrated in Fig. 8, or the cooling coil 72. of the unit illustrated in Fig. l. The outer layer of the coil 151i is provided with a series of discs 161. These discs 161, therefore, provide a greatly increased surface area for heat absorption from the gases passing thereover, and act to conduct the heat to the cooling medium which is flowing through the coil 16d.

It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention, or the scope of the subjoined claims.

Having thus described the invention, I claim:

1. A device for producing inert gas, comprising a housing having a gas collecting chamber therein, a partition mounted in said housing for supporting a fuel bed Vbelow said gas'collec'ting chamber and in spaced relationship withthe bottom of thehousing, nneans'providing va 'confined Vpassageway between the gas collecting Chamberland the .space below said fuel supporting partition, said passageway having openings into said gas collecting chamber at different distances from said fuel bed, means for introducing a pressure air stream into said passageway in a direction to entrain a portion of the gaseous products of combustion from said collecting chamber through said openings and to cause said air and said entrained gases to traverse said passageway for delivery to the fuel bed through said partition, means for conversely varying the size of said openings to control the portion of the collecting chamber from which the gaseous products of combustion are entrained into said passageway and to thereby regulate the temperature of the gases entrained in said air stream, and means for releasing a portion of the gases in said collecting chamber from said housing.

2. A device for producing an inert gas mixture, comprising a housing having a gas collecting chamber therein, la partition mounted in said housing for supporting a fuel bed below said gas collecting chamber and in spaced relationship with the bottom of the housing, aspirator means for entraining gases from spaced portions of said collecting chamber in an air stream and for introducing said air `and entrained gases to the spaces below said partition for delivery to said fuel bedthrough the partition, means for alternately varying the proportions of the gases entrained from said spaced portions of the collecting chamber to control the temperature of the gases entrained in said air stream, and means for removing a portion of the gases in theupper portion of said chamber from said housing.

3. A device for producing an inert gas mixture, comprising a housing having a gas collecting chamber therein, a perforated partition mounted in said housing for supporting a fuel bed below said gas collecting chamber and in spaced relationship with the bottom of the housing, an exhaust stack positioned above said collecting chamber to receive the gaseous products of combustion from the latter, cooling means within said exhaust stack, means providing a confined passageway between the gas collecting chamber and the space below said fuel supporting partition, meansfor directing a pressure air stream into the upper endV portion of said passageway to entrain gaseous products of combustion for delivery to the space below said partition, means providing a 'flow path from said collecting chamber to the upper end portion of said passageway, means providing a flow path from said stack to the upper end portion of said passageway, means for simultaneously opening one of said flow paths and closing the other, and means for withdrawing gases from the upper end portion of said stack.

4, A device of the type described, comprising a housing having a gascollecting chamber therein, a perforated partition mounted in said housing for supporting a fuel bed below said gas collecting chamber and in spaced relationship with the bottom of the housing, an exhaust stack positioned above said collecting chamber to receive the gaseous products of combustion from the latter, means for cooling the gases in said exhaust stack, means providing a flow path from said exhaust stack to the space below said partition, said flow path having an inlet in ysaidexhaust stack and an inlet in said collecting chamber, means for directing a pressure air stream into said flow path to induce the ilow of gaseous products of combustion therethrough, means for simultaneously opening one of said inlets and closing the other to control the ow of the gaseous products of lcombustion from said collecting chamber and said stack into the ow path and to thereby control the temperature of the air and gases in the space below said partition, and means for withdrawing a portion lof the gaseous products of combustion from said exhaustfstack. g v

' 5. device of 'the vtype described, kcomprising a'1 heus` '12 ing `-havinga gas collecting chamber therein, a'perforated partition mounted in said-housing vfor supporting a fuel bed 'below said gas collectingchamber and in spacedrrelationship 'with the bottom lof the housing, an exhaust stack positioned above said collecting chamber to receive the gaseous product of combustion from the latter, means for cooling ythe gases in said exhaust stack, a conduit having an'outlet opening belowsaid partition and one `set of inlet `openings; in said collecting chamber and a second set of inlet openings in the upper end portion of said stack, means for simultaneously closing one of said sets of inlet open-ings andopening the other set, means for directing a pressure air stream into said conduit below said one set ofinl'et openings to entrain gaseous products of Vcombustion through the open one of said sets of inlet Vopenings in said'conduit and to deliver said air and said entrained gases to the yspace below said partition, said opening and closing means acting to vary the temperature of said air and entrained gases by selection of the set of openings through which the gases are entrained, and means for releasing aportion off-the gaseous products of combustion from the exhaust stack.

6. A device of the typedescribed, comprising a housing having a gas-collecting chamber therein, a perforated partition mounted in 'said housing for supporting a fuel bed below said gas collecting chamber and in spaced relationship with ythe bottom of the housing, an exhaust stack positioned above said collecting chamber to receive n the'gaseous products of-combustion from the latter, means for cooling the gases in said exhaust stack, a conduit having an outlet opening below said partition and one set of inlet openings infsaid collecting chamber and a second set of inlet openings in the upper endportion of said stack, the section of saidfconduit between the set of inlet openings in saidl collecting chamber and the outlet opening having converging and diverging portions, means `for simultaneously closing one of said sets of inlet openings and opening the other set, means for directing a pressure air stream into the converging portion of said conduit to entrain gaseous products of combustion through the open one of said sets of inlet openings in said conduit and to deliver' said air and said entrained gases to the space below said partition, said opening and closing means acting to vary the temperature of said air and entrained gases by selection of the set of openings through which the gases are entrained, and means for releasing a portion of the gaseous products of combustion from the exhaust stack.

7.A device of the'type described, comprising a housing having a gas collecting chamber therein, a perforated partition mounted in said housing for supporting a fuel bed below said gas collecting chamber and in spaced relationship with the bottom of the housing, an exhaust stack positioned above said collecting chamber to receive the gaseous products of combustion from the latter, means for cooling the gases in said exhaust stack, a venturi having'an inlet' in said collecting chamber and an outlet below said partition, means for directing a pressure air stream into the 'in'l'et of said venturi to entrain gaseous products lof combustion and deliver said air and said entrained :gases'to the space below said partition, means for'directingasome of said gaseous products of combustion from lsaid collecting chamber to the inlet of said venturi, means for directing some of said gaseous products of combustion fromsaid .stack to the inlet of said venturi, means for simultaneously eifecting operation of one of said directing means and preventing operation of the other of said directing means, and means for releasing a portion of the gaseousproducts of combustion from the exhaust stack.

8. Adevice of the type described, comprising a housing 'having :a gas rcollecting chamber therein, a perforated partition -rnoun'te'dfin said housing for supporting a fuel bed below saidjgas `collecting chamber and in spaced relationship with the bottom of the housing, an exhaust stack positioned above said collecting chamber to receive the gaseous products of combustion from the latter, means for cooling the gases in said exhaust stack, a venturi having an inlet in said collecting chamber and an outlet below said partition, valve means for regulating the flow of gaseous products of combustion from the stack and from said collecting chamber to said venturi inlet, means for operating said valve means to alternately permit and stop the ow of gases from the stack and from the collecting chamber to the venturi inlet and to thereby control the temperature of the gases delivered to the space below said partition, and means for withdrawing gases from the upper portion of said stack.

9. A device of the type described, comprising a housing having a gas collecting chamber therein, a perforated partition mounted in said housing for supporting a fuel bed below said gas collecting chamber and in spaced relationship with the bottom of the housing, an exhaust stack positioned above said collecting chamber to receive the gaseous products of combustion from the latter, means for cooling the gases in said exhaust stack, a venturi having an inlet in said collecting chamber and an outlet below said partition, valve means for regulating the flow of gaseous products of combustion from the stack and from said collecting chamber to said venturi inlet, control means responsive to changes in the temperature of the air and entrained gases at the outlet of said venturi for operating said valve means to alternately permit and stop the flow of gases from the stack and from the collecting chamber to the venturi inlet, and means for withdrawing gases from the upper portion of said stack.

10. A device of the type described,comprising a housing having a gas collecting chamber therein, a perforated partition mounted in said housing for' supporting a fuel bed below said gas collecting chamber and in spaced relationship with the bottom of the housing, an exhaust stack positioned above said collecting chamber to receive the gaseous products of combustion from the latter, means for cooling the gases in said exhaust stack, a venturi having an inlet in said collecting chamber and an outlet below said partition, valve means for regulating the flow of gaseous products of combustion from the stack and from said combustion chamber to said venturi inlet, means providing for manual operation of said valve means to alternately permit and stop the ow of gases from the stack and from the collecting chamber to the venturi inlet and to thereby control the temperature of the gases delivered to the space below said partition, and means for withdrawing gases from the upper portion of said stack.

References Cited in the file of this patent UNITED STATES PATENTS 440,950 Kitson -2 Nov. 18, 1890 704,527 Evans et al 2 July l5, 1902 912,373 Hatton Feb. 16, 1909 1,984,665 Tone Dec. 18, 1934 2,085,586 Hotchkiss lune 29, 1937 2,278,204 Lewis Mar. 3l, 1942 2,301,044 Heard et al. Nov. 3, 1942 2,436,309 Koebel Feb. 17, 1948 2,585,441 Cornell et al. Feb. 12, 1952 2,585,462 Hirsch Feb. l2, 1952 

1. A DEVICE FOR PRODUCING INERT GAS, COMPRISING A HOUSING HAVING A GAS COLLECTING CHAMBER THEREIN, A PARTITION MOUNTED IN SAID HOUSING FOR SUPPORTING A FUEL BED BELOW SAID GAS COLLECTING CHAMBER AND IN SPACED RELATIONSHIP WITH THE BOTTOM OF THE HOUSING, MEANS PROVIDING A CONFINED PASSAGEWAY BETWEEN THE GAS COLLECTING CHAMBER AND THE SPACE BELOW SAID FUEL SUPPORTING PARTITION, SAID PASSAGEWAY HAVING OPENINGS INTO SAID GAS COLLECTING CHAMBER AT DIFFERENT DISTANCES FROM SAID FUEL BED, MEANS FOR INTRODUCING A PRESSURE AIR STREAM INTO SAID PASSAGEWAY IN A DIRECTION TO ENTRAIN A PORTION OF THE GASEOUS PRODUCTS OF COMBUSTION FROM SAID COLLECTING CHAMBER THROUGH SAID OPENINGS AND TO CAUSE SAID AIR AND SAID ENTRAINED GASES TO TRAVERSE SAID PASSAGEWAY FOR DELIVERY TO THE FUEL BED THROUGH SAID PARTITION, MEANS FOR CONVERSELY VARYING THE SIZE OF SAID OPENINGS TO CONTROL THE PORTION OF THE COLLECTING CHAMBER FROM WHICH THE GASEOUS PRODUCTS OF COMBUSTION ARE ENTRAINED INTO SAID 